1. Field of the Invention
This invention relates to the manufacture of composite containers and primarily to the assembly of a hollow sleeve preform on the neck and body portions of an inverted container for subsequent shrinking in situ thereon. The sleeve may be formed immediately prior to its application to the container. Alternately, the sleeve may be in preformed, flattened condition and taken to a position immediately above the container where it is fully opened and moved into co-axial alignment with the container held in inverted relation. The tubular sleeve is adapted to being opened and moved horizontally to co-axially align the two components for their telescopic assembly. The sleeve is deposited telescopically on the container body and neck while retained in precise vertical alignment. The final shrinking of the sleeve tightly around the body and neck portions can be performed by many appropriate physical conditions.
2. Description of Prior Art
This invention comprises an improvement over the methods and apparatus disclosed in issued U.S. Pat. Nos. 3,767,496, issued Oct. 23, 1973; 3,802,942 issued Apr. 9, 1974; and 3,959,065 issued May 25, 1976, all of which are commonly owned by the same assignee as the present application. In each of these disclosures, a tubular sleeve is formed which is telescopically assembled onto the article from below by a push-up mechanism. None of these disclosures pertain to a thin flexible sleeve of thermoplastic material which may be stored in flattened, prefabricated condition or fabricated just prior to use and then opened and telescoped downwardly over the inverted container in rapid and efficient assembly during their coincident lineal movement.
In many of the previously-disclosed processes and apparatus for making composite containers having an integral plastic base or sleeve thereon, a manufactured glass bottle or jar is loaded onto a conveyor and pre-heated prior to mounting the plastic sleeve. The plastic sleeves are carried on an underlying turret to pass into alignment with the bottles and are moved vertically upwardly into telescopic assembly over the lower ends or body portions of the bottles. The sleeves are then carried on the bottles into a heating apparatus such as a tunnel oven wherein appropriate physical conditions shrink the sleeves into close-fitting conforming arrangement over the bottle body surfaces where assembled. The heating apparatus commonly consists of a lengthwise oven through which the bottles are passed, the oven temperatures ranging from about 170.degree. F. to 800.degree. F., depending upon the plastic material selected to comprise the sleeves.
U.S. Pat. No. 3,959,065, owned by the common assignee of this application, discloses method and apparatus which assure against dislocation of the sleeve on the bottle without external handling mechanism being required to hold the sleeve in place between its assembly point with the bottle and the shrinking oven.
The cap sealing of bottles has been conventionally performed in recent years to provide for reasons of sanitation, pilfer-proofing, safety and appearance, the further step of placing over and around the neck of the bottle, as well as preferably over at least part of its closure, a tubular sleeve of heat-contracting synthetic resin material, severed to a prescribed length, and then shrinking the sleeve to conform to the bottle by thermal contraction. The synthetic resin tubing is usually pressed flat and delivered in rolls in many production processes, and since the tubing may or may not stay fully flattened, particularly where it is comprised of extremely flexible and resilient material, inefficiencies can and do result when the severed lengths of tubing are fitted onto the bottle necks. In some cases, to facilitate the fitting of short, flat, tubular sleeves onto the necks of bottles, it has been common practice to preform the sleeves such as by putting perforations or scores along their fold lines. It is also possible to apply the tubes around the bottle necks without preforming the material, as taught by U.S. Pat. No. 3,861,918 to Muto; however, such method normally requires the application of a bonding agent to the bottle neck for firm, permanent adherence of the sleeve. The method and apparatus disclosed by this patent are exceedingly more complex and prone to occasionally misapply a tubular band or label. U.S. Pat. No. 2,852,899 to Murrell discloses a collar feeding mechanism which is designed to remove only the lowermost collar from a nested stack by frictional engagement with its inner surface. The collars are preformed and nested tightly into a stack from which they are deliverable onto the container necks.
Normally when heat-shrinkable thermoplastic sleeves are mounted on containers such as bottles or jars having frustoconical upper portions, with the containers in upright relation for heat-shrinking an all-encompassing tubular sleeve therearound, the upper area of the sleeve when heat-softened tends to slump downwardly due to gravitational forces creating undesirable folds or wrinkles upon its shrinkage at such frusto-conical area. It is to solve this problem that the present invention is primarily directed.